Mona Chalabi “Why do Americans write the month before the day?” http://www.theguardian.com/news/datablog/2013/dec/16/why-do-americans-write-the-month-before-the-day
This condition is diagnosed as middle-endianness. Seriously. It comes from computer science where bytes are arranged according to their size. If the order has larger ones at the front, it's known as big-endian and so too are dates formatted with the years first (see the likes of China and Mongolia in the map above).
Even more bizarrely, computer scientists got their inspiration for the term 'endianness' from Jonathan Swift's 1726 epic Gulliver’s Travels*2. In the fictional kingdom of Lilliput people have to open their soft-boiled eggs at the small end (it's a royal decree). While in Blefuscu, eggs are cracked from the other end. Lilliputians are small-endians while Blefuscudians are big-endians. Again, seriously.
Jonathan Swift, like the computer scientists, was basically saying that systems are needed to organise even the most irrelevant seeming of things. As Danny Cohen*3 writes "Swift's point is that the difference between breaking the egg at the little-end and breaking it at the big-end is trivial… but we insist that everyone must do it in the same way, to avoid anarchy. Since the difference is trivial we may choose either way, but a decision must be made."